Acute and Sub-chronic Oral Toxicity Study of Ammonium Persulfate in Spraque-Dawley Rats

Yong Soon Kim,Min Won Baek,Jae Hyuck Sung,Hyun Youl Ryu,Jin Sik Kim,Hyun Sun Cho,Byung Gil Choi,Min Sub Song,Moon Yong Song,Eun Ju Baik,Young Kuk Choi,Jong Kyu Kim,Il Je Yu,Kyung Seuk Song 한국독성학회 2009 Toxicological Research Vol.25 No.3

The toxicity test of ammonium persulfate was conducted to ensure of its potential toxic effects according to the single-dose acute oral toxicity study (OECD Guideline 423) and 90-day repeated dose sub-chronic oral toxicity study guideline (OECD Guideline 408) for establishing national chemical management system, and matching in the Globally Harmonized Classification System (GHS) category. In acute oral toxicity study, pasty stool, perineal contamination and temporary body weight decrease were observed after dosing 1st and 2nd challenge (300 ㎎/㎏ body weight). All test animals were dead within 6 hours after dosing at 3rd challenge (2000 ㎎/㎏ body weight). Therefore, the GHS class of test substance is considered class 4. In sub-chronic toxicity study, body weight changes, food consumptions, hematological, biochemical and pathological examination did not show any noticeable and significant differences between the administered (5, 20, 80 ㎎/㎏ body weight) and control (vehicle only) group animals. Based on these results, the no observed adverse effect level (NOAEL) is considered above 80 mg/kg body weight.

Acute and Sub-chronic Oral Toxicity Study of Ammonium Persulfate in Spraque-Dawley Rats

Kim, Yong-Soon,Baek, Min-Won,Sung, Jae-Hyuck,Ryu, Hyun-Youl,Kim, Jin-Sik,Cho, Hyun-Sun,Choi, Byung-Gil,Song, Min-Sub,Song, Moon-Yong,Baik, Eun-Ju,Choi, Young-Kuk,Kim, Jong-Kyu,Yu, Il-Je,Song, Kyung-Se Korean Society of ToxicologyKorea Environmental Mu 2009 Toxicological Research Vol.26 No.3

The toxicity test of ammonium persulfate was conducted to ensure of its potential toxic effects according to the single-dose acute oral toxicity study (OECD Guideline 423) and 90-day repeated dose sub-chronic oral toxicity study guideline (OECD Guideline 408) for establishing national chemical management system, and matching in the Globally Harmonized Classification System (GHS) category. In acute oral toxicity study, pasty stool, perineal contamination and temporary body weight decrease were observed after dosing 1st and 2nd challenge (300 mg/kg body weight). All test animals were dead within 6 hours after dosing at 3rd challenge (2000 mg/kg body weight). Therefore, the GHS class of test substance is considered class 4. In sub-chronic toxicity study, body weight changes, food consumptions, hematological, biochemical and pathological examination did not show any noticeable and significant differences between the administered (5, 20, 80 mg/kg body weight) and control (vehicle only) group animals. Based on these results, the no observed adverse effect level (NOAEL) is considered above 80 mg/kg body weight.

사용자 편의를 고려한 시스템 요구사항 관리 데이터베이스 구축

진문섭,박찬영,최준호,정경렬,Jin, Moon-Sub,Park, Chan-Young,Choi, Chunho,Chung, Kyung-Ryul 대한기계학회 2013 대한기계학회 논문집. Transactions of the KSME. C, 산업기술과 혁신 Vol.1 No.2

국가 연구 개발 사업을 통해 수행된 도시형 자기 부상 열차 실용화 사업은 중저속 자기부상열차시스템 개발기술을 확보하고 시범노선 구축 및 시험운행을 통해 상용화를 목적으로 자기부상열차로서 국내에서는 최초의 상용화이며 완전무인운전시스템 구현을 목표하고 있다. 본 연구는 사업에 참여하는 기업, 연구소들의 시스템엔지니어링 활동의 핵심이라고 할 수 있는 도시형자기부상열차 시스템요구사항을 개발하고, 요구사항을 기반으로 도출된 추적성 기법을 제안하였다. 본 논문에서는 사업 전주기에 걸쳐 관리할 수 있는 체계를 정립하고, 카테고라이징 및 DB화를 통하여, 사용자 중심의 엔지니어링 도구를 개발함으로써, 도시형 자기부상열차 시스템의 개발 및 구축을 효과적으로 지원할 수 있도록 하였다. In this paper, a new system requirement management tool and its application on the Urban Transit Maglev Project were introduced. In most R&D projects on complexity system such as transportation system, Systems Engineering(SE) activities are included on each project, and SE teams are using commercial computer-based tools to perform the SE activities. Even though SE tools help to manage huge data and documents on engineering efficiently, but well-designed functions of SE tools which support SE activities are not sufficiently used on the whole process of system engineering. In order to computer-based SE tools are to be effectively used on project management, most engineers who takes engineering and coordination roles, at least sub-project managers should be familiar to the tool and could be easily use it, but usability of commercial SE tools are very difficult for normal engineers with no experience on SE activities and SE tools. To overcome this difficulty, we developed a new system requirement management tool considering each user's scenario on using engineering tools. The developed tool could not cover whole SE processes, but designed to perform requirement engineering such as system requirements(SRs) management, specification management, traceability management, SRs' verification activity management and so on. All the entities on SR database are inter-connected by pre-recognized traceabilities, so even non-specialists on SE can easily browse the database and find entities concern, and linked information such as interacted entities, legal or engineering constraints, coordination documents, status of development and verification and so on. Also functions for SR verification tools, TPM(Technical Performance Measure) tools, DB searching tools with traceability, and report generation tools are included on the system.

Clinical Manifestations and Treatment Outcomes of Eosinophilic Gastroenteritis in Children

Choi, Jong Sub,Choi, Shin Jie,Lee, Kyung Jae,Kim, Ahlee,Yoo, Jung Kyung,Yang, Hye Ran,Moon, Jin Soo,Chang, Ju Young,Ko, Jae Sung,Kang, Gyeong Hoon The Korean Society of Pediatric Gastroenterology 2015 Pediatric gastroenterology, hepatology & nutrition Vol.18 No.4

Purpose: The aim of the present study was to investigate the clinical features and outcome of eosinophilic gastroenteritis (EGE) in children. Methods: Our study enrolled 24 children who were diagnosed with EGE from 1993 to 2014 at the Department of Pediatrics, Seoul National University Children's Hospital. The patients' clinical manifestations, treatments, and outcomes were reviewed from the medical records. Results: The mean age at diagnosis was 5.3 years. Most patients had gastrointestinal symptoms including diarrhea (54.2%) and abdominal pain (45.8%). Peripheral eosinophilia was present in 91.7% of the patients. Thirteen patients (54.2%) showed anemia, and 15 patients (62.5%) had hypoalbuminemia. EGE was classified as mucosal, subserosal, or muscular in 75.0%, 20.8%, and 4.2% of cases, respectively. Three patients showed gastroduodenal ulcers upon endoscopic analysis. A history of allergy was reported in 13 patients, including atopic dermatitis, allergic rhinitis, and asthma. Five patients (20.8%) improved with food restrictions. Among the 19 patients treated with steroids, 11 (57.9%) discontinued steroid treatment without subsequent relapse, 4 (21.1%) relapsed after ceasing steroid treatment, and 4 (21.1%) showed no response to steroids. Two patients who were resistant to steroids underwent therapeutic surgery. The presence of gastroduodenal ulcers was significantly associated with relapse and steroid resistance. Conclusion: A high suspicion of EGE is warranted when children have nonspecific gastrointestinal symptoms and peripheral eosinophilia. Most patients improved with food restrictions or steroid treatment, although one-third of patients showed a relapse or steroid resistance.

Self-attribution of overconfident CEOs and asymmetric investment-cash flow sensitivity

Choi, Paul Moon Sub,Chung, Chune Young,Liu, Chang Elsevier 2018 NORTH AMERICAN JOURNAL OF ECONOMICS AND FINANCE Vol.46 No.-

<P><B>Abstract</B></P> <P>In this paper, we examine whether overconfidence coupled with a self-attribution bias affects the investment decisions of top corporate managers. First, overconfidence of chief executive officers appears to lead to the downward rigidity of investment-cash flow sensitivity. Additionally, overconfidence intensified by managerial self-attribution exacerbates the stickiness of investment-cash flow sensitivity. These results hold in both financially unconstrained and constrained firms with stronger results in the former. Overall, our findings are in line with the literature that lends support to the excessive investment commitment of overconfident managers.</P>

Corporate Transparency, Product Innovation, and Shareholder Value: Evidence from Korean Pharmaceutical Listings

Moon Sub Choi,Jong kuk Lee,Joonho Richard Hwang,Hwan oong Lee 한국무역연구원 2014 貿易 硏究 Vol.10 No.6

By constructing a novel proprietary pharmaceutical database, we assessed whether the corporate transparency of Korean exchange-listed pharmaceutical companies affects event-study returns upon Korea Food and Drug Agency approvals of new drugs. The empirical findings are as follows: First, the evidence is that new drugs are priced in the announcement returns. Second, product innovation is appraised higher by the investors when the company is well-governed in terms of trading venue, R&D intensity, balance sheet variables, payout policy, valuation, and years of operation. Lastly, shareholders are wealthier with innovative new products promised by trustworthy managers.

기업투명성과 신약 개발효과

최문섭(Choi, Moon Sub),이종국(Lee Jongkuk),김준희(Kim, Junhee) 한국상품학회 2012 商品學硏究 Vol.30 No.4

신제품 개발은 기업의 지속적 경쟁우위 및 기업 생존을 위한 핵심요소로 강조되어 왔다. 또한, 기존 연구들은 기업 경영의 투명성이 기업 자원의 효율적 활용을 위한 바탕이 됨을 제시하고 있으나, 기업투명성이 신약개발의 효과에 미치는 영향에 대한 실증적 연구는 없는 실정이다. 이에, 본 연구는 제약업체의 기업투명성이 신약허가 발표시 해당 종목의 조사기간 수익률에 어떠한 영향을 미치는가에 대해서 규명한다. 투자자들이 기업 내부정도에 노출된 정도를 통제했을 때, 신약의 혁신유형은 각기 상이한 경제적 부가가치를 창출하는 것으로 보인다. 또한, 주가수익률 동기성으로 추정된 기업투명성이 높은 제약업체일 수록 산약 허가발표시의 누적초과수익률 또한 개선된다. New product innovations are a key source of sustainable competitive advantage and firm survival. Although corporate transparency has been emphasized for efficient use of firm resources, we know little about the link between corporate transparency and firm value effect of new product innovations. In response, we assess whether corporate transparency of NYSE-listed pharmaceutical companies affects event-study returns upon announcements of FDA approvals. Controlled for investors’ relative exposure to inside information potentially pertaining to approval procedure, innovation types are priced in the announcement returns. Lastly, announcement returns are lower with a pharmaceutical firm lower in corporate transparency, proxied for by stock return synchronicity.

Agglomeration Effects and Foreign Direct Investment Location Choice

Paul Moon Sub Choi 한국무역학회 2019 한국무역학회 세미나 및 토론회 Vol.2019 No.4

transabdominal cervico-isthmic cerclage for the treatment of incompetent cervix: 8-years experience of 84 cases

( Jung Sub Choi ),( Moon Il Park ),( Jai Auk Lee ),( Hyung Moon ),( Youn Yeung Hwang ) 대한산부인과학회 1996 대한산부인과학회 학술대회 Vol.78 No.-

Agglomeration Effects and Foreign Direct Investment Location Choice: Cross-country Evidence from Asia

Paul Moon Sub Choi,Chune Young Chung,Kaun Y. Lee,Chang Liu 한국무역학회 2020 Journal of Korea trade Vol.24 No.1

Purpose – This study examines the determinants of foreign direct investment (FDI) location choice for Chinese firms, focusing on the agglomeration effect for firms of the same nationality. Design/methodology – The empirical data are China’s inward FDI from the top 19 economies (excluding tax havens and Taiwan) in terms of FDI during 1997–2015 and China’s outward FDI from the top 18 economies (excluding tax havens). This study uses a random effects generalized least squares model for panel data analysis. Findings – The results confirm that both host countries’ costs and market conditions and the degree of agglomeration affect these countries’ attractiveness for FDI inflows. Specifically, agglomeration has a significant effect on China’s inward and outward FDI. This study confirms that the agglomeration of firms of the same nationality has predictive power for multinational enterprises’ FDI location choices. The host countries’ real GDP and trade openness also positively affect FDI inflows. Interestingly, however, China’s production cost has a positive effect. Thus, inward FDI aimed at entering the Chinese market is increasing in recent years relative to the previous efficiency-seeking FDI. Inward FDI in China is therefore the market-entry type, whereas outward FDI by Chinese firms is the market-oriented type. Originality/value – These results suggest that the effects of the potential determinants of Chinese outward FDI are similar to those of inward FDI as China’s trade liberalization progresses.